The Belgium diffuser version was obviously a platform for further modifications which were seen at next race at Monza . The main tab fence gained the same arched patern of the diffuser roof but with less deep cut . The side curved tabs were replaced with enlarged and slotted ones .Finally the rear brake winglets were shaped back to Silverstone configuration .
The too many diffuser versions is not a surprise because red Bull raced also many different front wings which from their part effect and direct rear end modifications .
Two races ahead of Germany and Red Bull had one more new diffuser in Belgium . The new structure had a revised rear deformable structure with a full length winglet under the light to optimize the aero performance both above and below it . The inner vertical fences had regained their former height while the rear brake winglets were reshaped once again .
The new diffuser was tested first during free practice sessions on Friday with the aid of fluorescent paint to reveal flow details .
Interesting but promising updates took place on diffuser at Nurburgring . The new roof is now arched where the vertical fences meet the roof rather flat as was before . Red Bull RB6 also featured a similar diffuser concept last season . Additionally the inner vertical fences ( in yellow ) are now shortened to let a stronger air interaction between the two flows passing through the centre zone .
Red Bull in a quest of finding the optimum shaping of the rear brake winglets presented another revision at Silverstone as shown in the illustration below .
In Spain Red Bull had a new upgrade package featuring several rear end modifications . In particular the diffuser inherited a winglet under the rear deformable structure which blocks the hot air coming from the two outlets sitting on either gearbox bottom sides to enter the central diffuser section from above . So the only remaining access of those hot emissions to the diffuser is through the engine starter hole .
Another change is that the rear wing’s endplates gained vented extensions similar to the ones seen on Mc laren and Sauber quite a long time now .Worth’s remembering that Toyota was first to exploit those extensions back in 2009 to help diffuser extract air from under the floor more efficiently, because they divert air flow outwards.
Additionally the lower combo of the rear brake winglets were also new , being now angled upwards.
Following the sister team Toro Rosso’s steps, Red Bull presented a new diffuser at Melbourne with a slotted tab placed between the rear wing’s endplates . Furthermore the tab fence was also extended towards the diffuser’s side wall (all changes are highlighted in yellow color in the illustration above) . The concept behind the slotted tab idea is to let portions of air flow through the slot favoring drag reduction . In Toro Rosso case (Toro Rosso diffuser link) the slot is deeper indicating a stronger airflow towards the diffuser roof due mainly to STR6 twin floor configuration . A too large slot would of course effect diffuser functioning negatively .
As regards the rear brake winglets , the lower combo lost the endplate that kept the three fins joined together .
The first upgrades to diffuser came early at third Winter test at Barcelona . Actually Red Bull tested two different types of diffuser .
The first one had a hole under the rear deformable structure to permit hot air coming from car’s internal components, such as engine radiators , to access the diffuser main section and energize it . The hot air exits through two outlets that exist behind the diffuser roof and close to gearbox. Energizing the diffuser with radiator’s hot air is less efficient than exhaust gases both in heat energy that is transferred and also in flow velocity.
Barcelona test on March – Type A
Barcelona test on March – Type B
The second type had a revised fairing under the rear light which led to jack receptor changes as well (jack receptor help mechanics to lift the car up in a pit stop for tyre change ) .Moreover the gurney tab was chopped completely from the side walls close to wheels indicating a stronger flow through this zone . Another noticeable change is spotted on the rear brake winglets which are now increased in number and of different shape . (all changes in yellow , being pointed by red arrows)